Spanking pants
From LatexWiki - the free latex fetish encyclopedia
Spanking pants are panties with additional openings in the back designed to expose the buttocks.
The name spanking pants suggests that the wearer could be spanked on his or her bare bottom without removing or repositioning the panties. Also, if the bottom bulges through the holes it may look more inviting to some people as a spanking target.
However, this item may be worn for reasons other than spanking (for instance, humiliation).
